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E. REEVE.

CHANGE SPEED GEARING.

APPLICATION man SEPT. 25. 1918.

Patented Sept. 23, 1919.

afl\\ l? 7 VFIIX nnwnnn nnnvn, or BIRIVIING ENGLAND, nssrenon 'ro sxn'nrcn'rn LIMITED, or LONDON, new.

MENCD-EJLIVIA.

ANG-E-SPEED (HEARING.

Specification of Letters Patent.

Patented'Sept. as, rare.

Application filed fieptem'ber Q5, 1918. Serial No. $55,554.

To all whom it may concern Be it known that I, EDWARD .Rnuvn, a subject of the King of England, residing in Birmingham, England, have invented certain new and useful Improvements in Change-Speed Gearing, of which the following is a specification. I

This invention relates to change speed gearing of the' spur epicyclic t pe in which the change of speed ratios is edected by the aid of electroma etic clutches, the gear being more especia ly, but not exclusively, intended for use on motor vehicles.

One form of an electro-magnetic changespeed and reverse ear of the spur-wheel epicyclic type accor ing to this invention is characterized by a construction'such that the three co-axial sun-wheels employed therein, two driving and one driven, are not only coaxial but are of three different sizes; that the driven sun-wheel is larger than the other two; and that'the three planet-wheels which gear with them (a) are rigidly connected to one another and turn about a planeta axis parallel to the axis of the suns, and (b have the smallest of the three planets geared to the largest of the three suns whereby a reverse is obtainable as well as three forward speeds in the manner hereinafter explained; and that two of the forward speeds are obtained by holdin stationary the support of theplanetary s aft.

The accompanying drawing is a side elevation, partly in vertical central longitudinal section of a three-suns type of gear accordin to this invention.

t is to be understood that in the drawing the electro-magnetic clutches and brakes are indicated diagrammatically only and that the details of their construction and of the mounting of their armatures are not of the present invention and may be of any convenient type.

' With reference to the drawin a driving shaft A which may convenient y be operatedby petrol motor, turns in ball-bearmgs a? in the fixed stationary casin X of the mechanism. Two driving sun-w eels D E of different diameters, are free to turn independently of the drivingl shaft A with which they are co-axial. T e smaller wheel E of these two is fixed on a spindle cwhich is supported at the left-hand end by ballbearmgs a supported in a cavity in a disk A secured to the right-hand end of the drivin shaft A spindle e is suported in the hollow lefthand end of the driven spindle A. The larger, D of the two sun-wheels D E is provided with a sleeve 1) which encircles and can turn in relation to the spindle e by which it is supported. The driven spindle A which turns in a sleeve .9 hereinafter 'described, can be connected in any suitable manner to, say, the road-wheels of an automobile vehicle, or to any other device which thechange-speed gear is to actuate. The circular electro-magnets D and E of two electro-magnetic clutches are fixed to and turn with the disk A of the driving shaft A the arinatures U and E of these clutches D and E turn respectively with the disk D fixed to the sleeve D of the sunwheel D and with the disk E fixed to and turning with the spindle 6. Current conveyed by any suitable means to the electromagnets D and E, or either of them, enables the suns D and E or either of them, to be clutched to the disk A so as to turn with it and the driving shaft A A stationary circular electro-magnet G is fixed to the casing X and with the armature G carried on the disk D aforesaid, forms I ner. hereinafter described.

A planetary spindle B narallel to the driving and driven shafts A and A 1s mounted in bearings 12 in a support S which turns about an axis that is co-axial withthe driving shaft. This support rotates on bearings which at its left-hand end are con- The right-hand end of the stituted by the ball-bearings a supported on the outside of the sleeve D and at its right-hand end where it is provided with the sleeve 8 it is borne on ball-bearings s in the fixed casing K. On the planetary spindle B are three planetary pinions 1, 2, 3 which rotate on it and are fixed to one another and coaxial with it. These pinions gear respectively with the three sun-wheels D E A A stationary annular electro-magnet K is fixed to the stationary casing X; its arma ture S" is fixed to the rotatable support S, and by energizing the electro-magnet K the support S can be locked to the stationary casin X when required, when it is thus locke two of the forward speeds of the gear are obtained, as will be hereinafter described.

The operation of the device illustrated in the drawing will now be described. To obtain the first forward'speed the brake electro-magnet K is energized. This holds the support S stationary. The clutch E E is energized, whereupon the driving-shaft A drives the smaller sun-wheel E which in turn rotates the planet-pinion 2; the planetpinion 3 turning with 2, being in gear with the sun A rotates the latter and the driven shaft A with the same sense of rotation as that ofthe driving-shaft A To obtain the second forward speed, the support S is held stationary as before by the brake K, but the clutch D' is. energized instead of the clutch E, whereupon the larger of the two sun-wheels D is turned with the driving shaft and rotates the planet-pinion 1, which turning with the connected planet-pinion 3, rotates the driven sun-wheel A and shaft A faster than in the previous case, but in the same direction,

For the third forward speed a through or direct drive is obtained by energizing the clutches D and E simultaneously and releasing the brake K, this will result, by reason of the difierence in diameter of the planetary pinions 1 and 2, in the turning of these pinions and their support bodily in a motion of translation around the axis of the driving shaft, the planetary pinion. 3 being carried around with the other two and taking around with it the driven sun-wheel A and the shaft A at the same angular velocity as that of the driving shaft A and in the same sense.

For the obtainment of a reverse drive for the driven shaft A the brake G is enernized; this through the armature G", disk and sleeve D holds the sun-wheel D stationary. The clutch E is energized and this brings about the rotation of the sun-wheel E in the same direction as that of the driving-shaft. The sun-wheel E rotates the planetary pinion 2 and'with it the planetary pinion 1; the latter is thereby rolled around the rim of the stationary sunwheel D in the direction opposite to that in which the driving shaft is rotated. The planetary pinion 3 accompanies the planetary pinion 1 in this motion of rotation and translation and if it were of the same diameter as the latter it would leave the driven sun-Wheel A stationary; but as it is of smaller diameter than 1, it takes the driven sun-wheel A with it in the motion of translation, in the same direction as that motion,

namely a direction opposite to that in which of the unreversed sun-wheel E while the sun-wheel D remains stationary.

wThough only one planetary shaft B is shown in the drawing it is to be understood that there may be several of these shafts and the pinions on them, set parallel with one another at suitable equal angular intervals apart around the main axis of the mechanism, as is common in epicyolic gears.

In the construction shown in the drawing the gear-wheels are all inclosed in the support S which is a hollow casing; this can easily be made oil-tight so that the gear may be run in a lubricant of a kind diderent from that employed for the clutches, so that the best lubricant can be selected for the difl'erent conditions of working in the gear and in the clutches.

What I claim as my invention anddesire to secure by Letters Patent is 2-- In an elec'tro-magnetic change-speed and reverse gear of the spur-wheel epicyolic type comprislng a driving-shaft, two driving sunwheels 1) E of difierent diameters loose and turning on bearings that are coaxial with the driving shaft, two rotatable electro-magnetic clutches whereby they may be clutched to and released from the driving shaft selectively and collectively, and a stationary electro-magnetic brake whereby the larger of the two driving sunwheels can be looked to and released from the stationary casing of the mechanism, the employment in combination therewith of a driven sun-wheel A co-axial with but larger than the other two sun-wheels, a planetary spindle parallel to the driving shaft support "which turns about an axis that is coaxial with the driving-shaft, hearings on. the support for thesaid planetary spindle to revolve in three planetary pinions 1,2, 3 on and coaxial with the said planetary spindle rwhich pinions are llltl Tllh connected to one another and gear respecran rename tively with the three sun-wheels D E name to this specification in the presence of and another stationary electro magnetic two subscribing Witnesses. brake whereby the support aforesaid is looked to the stationary casing of the mech- EDWARD REEVE' 5 anism for the obtainment of two of the for- Witnesses:

- ward speeds as hereinbefore described. 7 A. JACOB,

In testimony whereof I have signed my J. ENomsH. 

